It is cold. Everywhere. It's so cold, even the high temperatures in some places are below zero. With cold weather comes increased risk of several kinds of health concerns. Here's a quick guide on what to do if you or a loved one is affected.

FrostbiteWhat is it? Skin tissue has frozen up. What does it look like? The affected area, usually extremities like fingers and toes, goes numb and turns grayish-yellow or white. I think I have it! What should I do? Seek medical help. Immerse frostbitten area in warm water. Don't rub it! Where can I learn more? Page 12 of this Center for Disease Control guide

HypothermiaWhat is it? The body is losing heat faster than it can replace it. What does it look like? The person may be shivering or confused and in severe cases can lose consciousness. If their temperature is below 95 degrees, it's an emergency. I think someone has it! How can I help? Move the person to a dry, warm place and give them a warm, sugary beverage without caffeine. If it's severe, call 911. Where can I learn more? Page 10 of the same guide

Trench footWhat is it? It's like a less severe version of frostbite, and it's only in the feet. What does it feel like? You'll have tingling or burning, and sometimes blisters. I think I have it! What should I do? Soak your feet in warm water. Drink a warm, sugary beverage. Where can I learn more? From the Occupational Health & Safety Adminsitration

InfluenzaHow widespread is the flu right now? Half of states were classified as having "widepsread" flu activity in the last week of December.Where is the flu most widespread? Many southeastern states are having their busiest flu season in 3-4 years, with some reporting several deaths already.How do I know if I have it? You might have the flu or a bad cold if you have a fever, coughing or extreme tiredness. I think I have one of those! What should I do? The flu is more serious, but it is sometimes impossible to tell the difference without running tests. Go see a doctor in case it's the flu. Where can I get more information? The CDC puts out a report every week and also has a flu section on its website.

Ice-related injuriesWhat risk is there on the ice? When you slip and fall, it can cause fractures, sprains or broken bones, especially in ankles and wrists.What should I do if I fall? If you think you hurt something, seek help sooner rather than later because your injury could get worse with time.

Carbon Monoxide (CO) PoisoningWhat is CO? It's a colorless, odorless gas that is emited from fuel-burning appliances, cars and combustion equipment. How can it poison you? The air can become dangerous for people and animals when CO is not allowed to vent, like when cars are left running in garages. What does CO poisoning look like? Symptoms include headache, dizziness and confusion. I think I have it! What should I do? CO poisoning can turn deadly quickly. Turn off the appliance and leave the affected area immediately. Then seek medical attention. Where can I learn more? From this CDC fact page and the Department of Housing and Urban Development